Such a steering is known from, for example, DE 102 57 130 A1. The steering valve has a valve slide with power assisted activation. When displacing the valve slide, a path from the supply connection arrangement to the steering motor is more or less released, so that the steering motor is activated.
A similar embodiment is shown in the later published German patent application 10 2004 021 351.
When the steering valve is hydraulically activated, leakages inside the steering that cannot be avoided cause the risk that the steering valve is activated, even though this is not desired.